Table 3 Procedures for assessing DRS-R98 items relevant to DSM-5 criteria for delirium

A disturbance in attention

DRS-R98 item 10 Attention score ≥1

and awareness with reduced orientation to the environment

DRS-R98 item 9 Orientation score ≥1

The disturbance develops over a short period of time (usually hours to a few days)

DRS-R98 item 14 Temporal Onset ≥1

represents a change from baseline attention and awareness, and tends to fluctuate in severity during the course of a day

DRS-R98 item 15 Fluctuation score ≥1

An additional disturbance in cognition (e.g. memory deficit, disorientation, language, visuospatial ability, or perception

Any of the following: score of ≥1 on DRS-R98 item 11 Short term memory, item 9 Orientation, and Score of ≥2 on DRS-R98 item 5 Language, item 13 Visuospatial, item 2 Perceptual disturbance.

The disturbances in Criteria A and C are not better explained by a pre-existing, established or evolving neurocognitive disorder and do not occur in the context of a severely reduced level of arousal, such as coma.

Where dementia is present, a total DRS-R98 score of ≥18 denoted presence of comorbid delirium

There is evidence from the history, physical examination or laboratory findings that the disturbance is a direct physiological consequence of another medical condition, substance intoxication or withdrawal, or exposure to a toxin, or is due to multiple etiologies

DRS-R98 item 16 Etiology score ≥1